This invention relates generally to a cable connector having a coupling member to connect it to other connectors, equipment ports, or the like. Specifically, this invention relates to an improved sealing arrangement for preventing moisture from penetrating at a joint between the coupling member and the body of the connector.
Cable telecommunication systems have evolved and flourished to provide many cable telecommunication services, such as digital television programming, voice over internet protocol (VOIP) services, broadband internet, and pay-per-view ordering/billing/monitoring. With the growing population and the growing demand for cable telecommunication services, cable telecommunication systems have continually expanded since their inception in the 1940's. Today, cable telecommunication services are delivered to millions of users (e.g. at residential or commercial premises) by feeder cables running from head ends. A head end receives and retransmits video and other signals over a local cable infrastructure along feeder cables, which branch off to individual user's facilities along drop cables. These drop cables can be further divided to distribute signals along distribution cables on a user's facility to multiple end devices, such as televisions or modems.
As can be envisioned from the above description, cable does not run as a single length from a head end to each and every end device. In routing the feeder cables, drop cables, and distribution cables to feed the signals to all the users in a local cable infrastructure, multiple lengths of each cable type (e.g. feeder cable, drop cable, distribution cable) are necessary. Cable connectors can join one length of one type of cable to another length of the same type of cable in order to form a consistent signal path with consistent signal qualities. In the case of coaxial cables, which are currently used to feed and distribute telecommunication signals, the signals are in the form of alternating electrical current, so coaxial cable connectors connecting two lengths of the same cable are designed and used to pass a consistent alternating electrical current without altering the electrical characteristics.
Alternatively, one length of one type of cable can be joined by a coaxial cable connector to another length of another type. Further, a cable can be connected to an end device or other intermediate device by a cable connector.
In order to accommodate the various combinations of connection, including connections between the variously sized cables with various electrical characteristics, a large variety of cable connectors exist. These connectors are used extensively, and more and more as the cable telecommunication systems continue to develop and grow. A large percentage of these cable connectors are used outside, while another percentage of them are used inside a residential, commercial, or industrial property. Many are located underground, connecting underground cables, while some are exposed to the air.
Both indoors and outdoors, the cable connectors are subject to environmental hazards and weathering elements, such as damage from exterior matter, including water. In particular, especially with cable connectors used outdoors, water poses a significant threat of damage. Some forms of water include, but are not limited to, rain, condensation, high relative humidity, and flooding. Even indoors, connectors are exposed to water, especially in basements, where they are frequently used. When water gets inside a connector, it can cause significant and costly damage. In particular, water can catalyze corrosion. Corroded parts can negatively affect the electrical characteristics of the cable connector, which can negatively alter signals carried along conductors therein. Water itself in a connector, even without corrosion occurring, can negatively affect the electrical signal characteristics too. A short to ground from the conductor might occur, thereby stopping the signal from reaching its destination altogether. Any malfunction or degradation of the connector requires maintenance, as even minor signal alteration can cause major problems, for example, with the viewing of a video image. Alteration, or loss of desirable signals can cause some form of disruption in the telecommunication services provided to a user. For instance, television programming images can be distorted, broken, or choppy, while internet connections can be slowed or transmissions lost, and VOIP services can be slowed, rendered inaudible, or lost. Furthermore, minor losses in signals returning or sent from user facilities build up in cable telecommunication systems to reduce overall signal to noise ratios. To prevent this buildup of signal loss, connectors must be maintained and repaired. Maintenance is costly. The problems must be diagnosed. Once identified as a connector issue, connectors must be accessed and repaired, often by digging to expose them, or by accessing them on or in a user's facility. Prolonging the life of connectors by avoiding water damage can save time and money.
Cable connectors connect, or mate, with other mating connectors in various ways. Some connections are fairly static. For instance, a male cable connector might merely plug directly into a female version of the cable connector with no moving parts attached to either connector. Other connectors might have a coupling member that rotates in some way, allowing the attached cables to resist rotation. For instance, a male connector might have an externally threaded coupling member which screws into an internally threaded female member; or the female connector might have internal threads that screw onto a male version of the cable connector. In this second type of connector, at least one coupling member of either the male or female connector must be able to freely rotate but still be attached to the connector. This feature creates a joint between the coupling member and the body of the connector. When the coupling member is screwed tight in connection to another connector, the coupling member is also pulled tightly against the connector to which it is attached. The friction between the coupling member and connector affects the coupling member's ability to freely rotate.
Such a joint creates an opportunity for water intrusion. A potential water hazard is greater at a moveable joint than a stationary joint because it can be more difficult to maintain a seal at the moveable joint. The extra motion provides greater opportunity for damage to the seal. The coupling member also may not be fully engaged and tightened, or it can loosen, thereby leaving extra space for water to enter. Moving parts also can wear the joint and any seal between them, creating an extra need for durability. Non-durable parts at the joint might wear quickly, degrading the seal and providing water a greater opportunity to enter.
The prior art is generally cognizant of sealing exposed joints where water can intrude. At the rotatable joint between a coupling member and a connector body, one typical sealing solution employs an o-ring. A groove either inside the coupling member or outside the connector body typically retains the o-ring. When the coupling member is secured onto and around the connector body, the o-ring fits snugly between the two parts, providing a seal.
Another typical solution involves the use of a sleeve. One type of sleeve is slipped on a first connector. When a second connector is mated to the first, the sleeve either covers the connection, or can be repositioned to cover the connection between the two mated connectors. This type of sleeve does not protect the joint between the connector body and the coupling member. Another type of sleeve is slipped onto a coaxial cable. From there, it is able to be repositioned to cover the end connector attached to the coaxial cable, as well as a second connector mated to the first connector.
These solutions require additional parts that can pose manufacturing difficulties and expense. Furthermore, separate o-rings and sleeves are sometimes handled or installed improperly causing the seals to function unreliably or ineffectively. For example, an o-ring might be out of its proper position when the installer secures the connection. In this case, the o-ring does not seal properly, and it might become damaged. Sliding a sleeve over the outside of a connector can cause tears or abrasions. The sleeve might again not be positioned properly over the intended area of protection. Otherwise, the sleeve might bunch or fold, preventing it from fitting tightly and sealing on the connector surface. Still other times, cable installers do not use the seals at all when installing the connectors. Each of these cases results in the undesirable case of a connector that is water-penetrable.
It would be advantageous to seal the joint between the coupling member and connector body without requiring additional assembly steps, without requiring additional parts, and without relying solely on cable installers to properly install connector seals.